Vehicle seat having an anti-submarining device and method

ABSTRACT

The invention relates to vehicle seat comprising a seat part and to a restraint device and a corresponding method of manufacture. The vehicle seat comprises an anti-submarining restraint device for preventing an occupant from slipping through on the vehicle seat when decelerated due to a crash, said restraint device being settable to a retracted inactive position and said restraint device being settable to an extended active position. The seat part, in the longitudinal direction of the vehicle, has lateral seat parts on both sides of the seat, a padding defining a seat area and a padding support ( 34 ) below said padding. The restraint device also comprises a tilting element ( 24 ) between the padding support and the padding and spaced apart from the lateral parts, said tilting element having at least one deformable element ( 24 ) as an energy dissipation element.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a National Stage filing and claims priorityto International Application No. PCT/EP2007/005593, filed Jun. 25, 2007,entitled “VEHICLE SEAT COMPRISING A SEAT PART AND AN ANTI-SUBMARINLNGRESTRAINT DEVICE, RESTRAINT DEVICE AND METHOD OF MANUFACTURE” whichclaims priority to German Patent Application No. DE 10 2006 029 330.4filed Jun. 23, 2006, the entire disclosures of which are incorporatedherein by reference.

The present invention relates to a vehicle seat with a seat section andwith a restraint device for preventing submarining of a passenger on thevehicle seat during an accident-induced deceleration, wherein therestraint device can be set in a retracted inactive position, andwherein the restraint device can be set in an extended active position,wherein the seat section has a padding, which defines a seat surface,and a padding support which is provided beneath the padding.

Such vehicle seats are generally known. For example, a motor vehicleseat with a seat surface on the surface of a padding is known fromGerman laid-open specification DE 102 31 794 A1, wherein a seat pan isprovided beneath the seat surface, and wherein between the seat pan andthe seat surface of the seat section a U-shaped adjusting element isarranged, which in the case of a crash can be moved out from an initialposition in such a way that the seat surface and the adjusting elementcounteract a forward displacement in the longitudinal direction of thevehicle of the pelvis of a person sitting on the seat surface. With thisvehicle seat, the adjusting element is configured such that it can beplastically deformed by a force exerted by the user (in particular by auser's pelvis). This has the disadvantage that only a relatively smallpotential force transmission surface for retarding the user is provided,this being associated, in the event of a crash, with correspondinglyhigh forces to be transmitted per surface area. Furthermore, the knownvehicle seat has the disadvantage that for realizing an active restraintdevice for preventing submarining of a person sitting on the vehicleseat (a so-called anti-submarining restraint device), i.e. a restraintdevice which can be transferred from an inactive to an active extendedposition, it is provided as a rule that the restraint device, duringassembly of the vehicle seat, must be connected to structural elementsof the vehicle seat, such as seat side sections or a seat section frameor the like, as a result of which there is no modularity in the sense ofthe possibility of deciding only at a late stage of the seat productionor of the seat completion whether the vehicle seat is to be equippedwith a restraint device or not. In the case of known vehicle seats,therefore, a larger number of variants of the vehicle seat have to betaken into consideration over a larger part of the production chain ofthe vehicle seat, which altogether leads to higher cost in the case oflogistics and production. A vehicle seat with a seat frame, a seatcushion and a seat cushion support is known from German laid-openspecification DE 199 43 595 A1, wherein in the longitudinal direction ananti-submarining ramp is attached approximately in the middle of theseat padding support, extends to the front edge of the seat paddingsupport and covers approximately the front half of the seat paddingsupport. A normally folded-up airbag, which is inflated in the event ofa crash, is provided between the ramp and the seat padding support, oris embedded in the ramp. However, an airbag of this type iscomparatively expensive, and therefore the known vehicle seat iscomparatively costly overall.

The present invention is therefore based on the object of providing avehicle seat with a restraint device for preventing submarining of apassenger on the vehicle seat in the case of an accident-induceddeceleration, wherein the vehicle seat for one thing can be equippedwith such a restraint device easily and simply with the least possiblecost and as late as possible in the production chain of the vehicleseat, and wherein for another thing the restraint device is equipped insuch a way that the surface pressure during the force transmission (inan accident situation) between a user and the restraint device is keptas small as possible.

The object is achieved by means of a vehicle seat with a seat sectionand with a restraint device for preventing submarining of a passenger onthe vehicle seat, wherein the restraint device can be set in a retractedinactive position, and wherein the restraint device can be set in anextended active position, wherein the seat section, in the longitudinaldirection of the vehicle, has side sections on both sides, wherein theseat section has a padding which defines a seat surface, and a paddingsupport which is provided beneath the padding, and wherein in additionthe restraint device has a positioning element between the paddingsupport and the padding and also at a distance from the seat sidesections, and an upper section between the positioning element and thepadding, and wherein the positioning element and/or the upper sectionhas/have at least one deformation element as the energy dissipationmeans. As a result of this, it is advantageously possible that for onething the modularity of the restraint device is ensured, i.e. thepossibility of deciding only at a late point in time in the productionchain of the vehicle seat whether a specific vehicle seat is to beequipped with a restraint device according to the invention or not. Foranother thing, this is possible by the correct functionality of therestraint device being able to be ensured in an especially easy and safemanner, wherein, in particular, the surface pressure (i.e. theapplication of force per surface area) between body parts of a user onthe vehicle seat (in particular the pelvis region) and the restraintdevice can be reduced within the course of an accident situation withthe effect of reducing the maximum value. By varying the energydissipation properties of the positioning element and/or of the uppersection, it is advantageously possible, according to the presentinvention, to permit adaptation (application) to different types ofvehicle particularly easily and cost-effectively. According to theinvention, it is especially preferred if the restraint device has anactuating means, especially a pyrotechnic linear actuator and/or areversibly operating actuator, wherein the actuating means is arrangedbetween the padding support and the padding, or is supported between thepadding support and the padding, wherein in particular an operation ofthe actuating means is already provided in terms of time before theexistence of an accident-induced deceleration. In the case of supportingthe actuating means between the padding support and the padding, theactuating means can partially also extend or be arranged beneath thepadding support. Linear actuators are comparatively small and can berealized in a compact manner in terms of installation space, so that asa result of this the restraint device can be configured in an especiallycompact manner in terms of installation space and according to theinvention the modularized installation method of the restraint device inthe vehicle seat can be especially easily realized. In the sense of thepresent invention, a padding support is understood to be a singlestructural component or a multiplicity of structural components of theseat section, which are provided at least in the proximity of thepadding which is possibly to be fastened later on the seat, and whichretain or support the padding. For example a padding support whichcontinues essentially over the entire seat surface, as an essentiallyuniversal cushion pan or seat pan is a possibility as a padding supportin this case. Furthermore, according to the invention, for example aso-called split seat pan or divided seat pan is a possibility, in whichsuch a split seat pan supports approximately the front half or only thefront or rear approximately 20% or just 10% of the padding. Furthermore,structural elements such as tubular or open stiffening elements are alsoa possibility as part of the padding support. In the case of a paddingsupport in the sense of the present invention this can also partiallyhave an underspringing. According to the invention, for example apyrotechnic linear actuator, also a reversibly operating actuatingmeans, for example an electric motor-powered linear actuator, can beprovided alternatively or cumulatively to an irreversibly operatingactuating means and together with corresponding sensors (pre-crashsensors) which anticipate an accident, leads to a setting of theextended active position of the restraint device or to a setting of anintermediate position of the restraint device (between the inactiveposition and the active extended position) already before an accidentoccurrence in terms of time and therefore before the existence in termsof time of an accident-induced deceleration (i.e. a deceleration whichis typical for an accident occurrence).

Furthermore, it is preferred if the restraint device has a positioningelement which is movable by the actuating means, wherein the positioningelement is adjustable by means of the actuating means from a retractedposition which corresponds to the inactive position of the restraintdevice into an extended position which corresponds to the activeposition of the restraint device. As a result of this, it is possiblethat the positioning element can be optimized to the respectiveapplication case independently of the actuating means, for example withregard its compressibility (for example for energy dissipation during anaccident situation), or also with regard to its dimensions which intheir turn for example have an influence on the extension degree of therestraint device.

Furthermore, it is preferred that a rotation around an axis whichextends essentially horizontally and especially transversely to thedirection of the vehicle is provided between the retracted position andthe extended position of the positioning element, wherein thepositioning element is preferably provided as a plate-form positioningelement, and wherein the rotation around the essentially horizontallyextending axis is preferably provided as a rotation in the direction oftravel. As a result of this, a plate can be used as the positioningelement which extends essentially over the entire width of the restraintdevice which can preferably be installed in a modular manner, whereinthe plate in the retracted position of the positioning element isarranged essentially parallel to the seat surface or parallel to thepadding support, and in the extended position of the positioning elementis arranged essentially perpendicularly to the seat surface orperpendicularly to the padding support. Between the positioning elementand the padding of the seat section, according to the invention there ispreferably the upper section in the form of a cover of the restraintdevice in the sense of an anti-submarining ramp. As a result of this, itis advantageously ensured that the body of the seat's occupant in thecase of an accident situation (i.e. a negative acceleration or adeceleration, which exceeds a prespecified limiting value) exerts aforce action upon the restraint device over the largest possible area sothat the risk of injury of the seat's occupant is lessened. A particularadvantage of a movement of the positioning element in the direction ofthe vehicle is that the force action of the actuating means, especiallya pyrotechnic linear actuator, can be selected in such a way that theforce action of the actuating means or its extension in any case is notdirected in the direction of main body parts (especially in thedirection of the pelvis or in the direction of the trunk) of the seat'soccupant. As a result of this, the risk of injury is likewise reduced.

According to the invention, it is additionally preferred that a rotationat least of a part of the positioning element around an axis, whichextends essentially vertically, is provided between the retractedposition and the extended position of the positioning element, whereinthe positioning element is preferably provided as a telescopicallyextendable positioning element with one or more extendable elements. Asa result of this, it is advantageously possible that the positioningelement can be realized in a compact type of construction, for exampleby means of cup-like components which telescopically inter-engage, andfor realizing the extended position from the retracted position arotational movement of at least one of the cup-like components aroundits center is carried out. In this case, a spirally designedpin-and-slot guide of the at least two cup-like components is preferablyprovided according to the invention for converting the rotationalmovement into an extending movement. For realizing a locking of such apositioning means, the pin-and-slot guide can be configured by means offor example an asymmetrical toothing in such a way that only a movementin the direction of the extending movement is possible. Alternatively toan exemplary pin-and-slot guide, in the case of the telescopicallyextendable variant of the positioning element it can also be providedaccording to the invention that for example two cup-like componentsinter-engage like a thread and by means of a rotation of one of thesecomponents relative to the other a positioning is brought about.

Furthermore, it is preferred if the positioning element and/or the uppersection has/have a plurality of material zones of differing material,wherein different material zones have a different deformation behavior,or if the positioning element and/or the upper section is/are providedin an at least partially reversibly deformable manner, wherein thepositioning element preferably has a shock absorber or a gas-pressuredamper or a plurality of such elements. By this means, it isadvantageously possible according to the invention for a differentdeformation behavior to be realized for accident situations of differingseverity or forces of differing strength to be transmitted between theuser of the vehicle seat and the vehicle seat. Furthermore, it isparticularly advantageously possible according to the invention that, onaccount of a different, accident-induced loading situation of thepositioning element or of the upper section caused by a certain seatposition or caused by certain force transmission ratios because of theuser's height, a deformation behavior of the restraint device, whichdeformation behavior is matched to the particular situation, takesplace.

It is particularly preferred if the restraint device has a furtherdeformation element. By this means, it is possible to even bettercoordinate the deformation response of the restraint device to a givenaccident situation.

Furthermore, it is preferred if the restraint device has a lower sectionand an upper section, wherein the lower section has fastening elementsfor connecting the restraint device to the padding support, or if thepadding support has fastening elements for connecting the restraintdevice to the padding support. As a result of this, it is possible in asimple manner to create the connection between the restraint device andthe padding support without expensive tools being required for it orwithout the task making high qualification demands. In this case,according to the invention a fastening by pushing on, or sliding on, orclipping, or adhesive fastening have proved to be especially preferable.Combinations of two or more such fastening possibilities can also beused, for example for securing a push-on connection or a slide-onconnection. Alternatively to the embodiment variant of the restraintdevice with a lower section and an upper section, it can also beprovided according to the invention that the functionality of the lowersection (for example the provision of connecting points of levers or thelike) is undertaken by the padding support (full integration of thelower section into the padding support) and that consequently the lowersection can be saved so that the weight can be reduced and costs can besaved. For example, it is provided in this case that the restraintdevice, that is to say for example lever connections or the like of therestraint device, are screwed and/or riveted and/or pinned to the lowersection.

Furthermore, it is preferred according to the invention that therestraint device has a locking means, wherein the locking means ispreferably provided in a movable manner by means of the movement of thepositioning element, wherein, in particular, the locking means has aslot and a bolt, wherein the bolt has an axial first section withreduced diameter, and an axial second section with enlarged diameter,and wherein an axial movement of the bolt is provided for bringing aboutthe locking. For example, it is possible according to the invention thata drag lever on its end opposite the positioning element is guided in ahousing which accommodates a multiplicity of spring-loaded latchingbolts which in the retracted position of the positioning element pressupon the drag lever. As soon as the drag lever has extended far enoughin the direction of the extended position of the positioning element,one of the latching bolts locks the return movement of the drag lever.By a multiplicity of such latching bolts a multiplicity of engagedpositions can be defined. This is especially advantageous in case (onaccount of malfunction of the actuating means or on account of theparticular situation of a seat occupancy for example by an abnormallylarge or an abnormally small person as the seat occupant) a movement ofthe positioning element into its furthermost extended position is notcarried out. A further embodiment variant of the restraint device foralternative realization of a locking means, according to the inventioncan provide a slot with a starting section and with an end section,wherein a bolt, which is moved together with the positioning element,engages in the slot, wherein the bolt in the inactive position of therestraint device is located in the starting section of the slot, and inthe active position of the restraint device is located in the endsection of the slot, and wherein the shape of the slot is configured insuch a way that at least in the (fully) activated position, or activeposition, of the restraint device a reverse movement of the positioningelement or of the bolt is prevented. In this case, the slot, accordingto a further variant of the locking means, can have for example acurvature or a bend point in such a way that the bolt which is movedwith the positioning element can no longer be moved back into thestarting section, or such a reverse movement is highly improbable, onaccount of the force ratios which exist in an accident situation.Furthermore, in a further variant an operating cam, also with a startingsection and an end section for a bolt, can be provided instead of theslot, wherein the operating cam has a recess in the end section in sucha way that the bolt which is moved with the positioning element likewisecan no longer be moved back into the starting section, or such a reversemovement is highly improbable, on account of the force ratios whichexist in an accident situation. In this case, it can preferably beprovided that the element or component which features the operating camis spring-preloaded in the direction of the inactive position. In thecase of the embodiment variants with a slot, it can be advantageouslyprovided in the same way that the element or component which featuresthe slot is spring-preloaded in the direction of the inactive position.Furthermore, in a further variant, a slot, in a way in which it isconfigured in the style of a keyhole, can be formed with a startingsection which has a reduced clear opening, and an end section which hasan enlarged clear opening, in such a way, and interacting with a bolt,that the bolt has a smaller diameter in a first axial section andinteracts with the starting section, and that the bolt, upon reachingthe end section of the slot (which is to be carried out during amovement of the positioning element in the direction of the activeposition), with a second axial section of the bolt, which has a largerdiameter, is pressed into the end section on account of aspring-pretensioning of the bolt. In a further embodiment variant of therestraint device, for alternative realization of a locking means,according to the invention the positioning element can interact with theupper section, especially with holes or recesses, in such a way thatupon reaching the active position a reverse movement of the positioningelement is prevented. According to the invention, it is furthermoreprovided that partial aspects of the different variants of the restraintdevice with a locking means can be combined with each other. In thisway, for example the last-mentioned variant (holes or recesses in thepositioning element) can be combined with the other variants.

Further subjects of the present invention relate to a restraint deviceaccording to the invention for a vehicle seat, and also to a method forproducing a vehicle seat according to the invention, wherein in a firststep the supporting structure of the vehicle seat is produced, andwherein in a second step the restraint device is connected to thepadding support. As a result of this, it is especially possible that thecomplete production steps for producing the structural elements of thevehicle seat, for example the frame of the seat, the frame of a backsection, the sub-construction of the seat section and the like, arecarried out in the first production step and for example are undertakenin the factory of the seat section manufacturer. The integration of therestraint device into the vehicle seat, or with the seat section ofthose vehicle seats which are to be equipped with the restraint device,can then be undertaken in a production plant in the proximity of thefinal production of the vehicle seat or of the vehicle in which thevehicle seat is to be installed, wherein for this installation of therestraint device in the vehicle seat according to the invention thereare significantly lower equipping requirements and furthermoresignificantly less qualification requirements of the employees who carryout the installation than for the production of the structural elementsof the vehicle seat for which for example the production of weldedjoints is necessary.

Exemplary embodiments of the invention are shown in the drawing andexplained in more detail in the following description.

FIG. 1 schematically shows a side view of a vehicle seat according tothe invention, and also shows a perspective view of a seat pan or of apadding support of a seat section of a vehicle seat according to theinvention with a partially sectioned view of a restraint deviceaccording to the invention.

FIG. 2 schematically shows a perspective view of a seat pan or of apadding support of a seat section together with the seat side sectionsof the seat section of the vehicle seat according to the invention witha view of the restraint device according to the invention.

FIGS. 1 a and 1 b schematically show perspective views of differentembodiments of a padding support of a seat section together with theseat side sections of the seat section and the restraint device.

FIGS. 3 and 4 schematically show in perspective view a seat pan or apadding support of a vehicle seat according to the invention with anembodiment of the restraint device in its inactive position (FIG. 3) orin its active position (FIG. 4).

FIGS. 4 a, 4 b and 4 c shows embodiment variants of the restraint devicein side view or in perspective view.

FIGS. 5, 6, 7 and 7 a schematically show in side view in each case adetail of the restraint device according to the invention with in eachcase an embodiment of an energy dissipation means.

FIG. 8 schematically shows in side view a detail of the restraint deviceaccording to the invention with a further embodiment of a positioningelement.

FIGS. 9 a, 9 b, 9 c, 9 d, 9 e, 9 f, 9 g, 9 h, 9 i, 9 j, 9 k and 9 l showembodiment variants of the restraint device in perspective view.

In FIG. 1 (in the left-hand part of the figure), a side view of avehicle seat 10 according to the invention is schematically shown. Thevehicle seat 10 comprises a seat section 30 and also as a rule a backsection which is not provided with a designation. According to theinvention, the seat section 30 especially has a frame-like structurewith at least two seat side sections 31 on the sides. Inside thisframe-like structure the seat section 30 has a seat pan 34 or a paddingsupport 34. A padding 33 or a seat cushion 33 is connected to the seatpan 34 or to the padding support 34. The seat section 30 is connected tothe floor sub-assembly 16 of the vehicle interior or to the bodystructure 16 of the vehicle by means of a seat substructure 15. By meansof the seat substructure 15 it can be provided according to theinvention that the complete vehicle seat 10 is connected in alongitudinally adjustable and/or vertically adjustable and/or inclinablyadjustable manner. For this purpose, in the left-hand part of FIG. 1 theseat substructure is shown as outlined links which by rotating orpivoting can bring about a corresponding seat setting. The padding 33has a seat surface 32 upon which a user of the vehicle seat 10, or anoccupant of the vehicle, or a passenger can be seated. According to theinvention, it is provided in an especially preferred manner that theseat pan 34 or the padding support 34 together with the padding 33 andthe seat surface 32 is provided in a vertically and/or inclinablyadjustable manner in relation to the rest of the seat section 30.

The seat section 30 of the vehicle seat 10 according to the inventionfor example can be provided as a two-times, or four-times, or six-times,or eight-times, or multiply adjustable substructure, as a result ofwhich for example the seat height and/or the seat inclination and/or theseat longitudinal adjustment and/or the seat length setting (thighsupport length) can be set. The padding support is shown in the figureslargely as a separate and one-piece seat pan 34 or as a correspondingpadding support 34, but can also be provided as a split padding support34 or a corresponding seat pan 34, as can be seen with reference to theexamples of embodiment variants of a padding support 34 which are shownin FIGS. 1 a and 1 b. A single structural component or a multiplicity ofstructural components of the seat section are especially understood as apadding support, which are at least adjacent to a padding of the seat orare provided in the proximity of such a padding, for exampleapproximately at a maximum distance of about 10 mm from such a padding,and wherein such a padding is carried, or supported or retained, by thepadding support or by its components. As a padding support, in this casefor example a continuous padding support (cushion pan or seat pan) (FIG.1), or a split seat pan, or split seat bucket (FIG. 1 a), are apossibility, or even structural elements such as tubular or openstiffening elements (FIG. 1 b) as part of the padding support.

According to the invention, a restraint device 20 is arranged betweenthe padding support 34 and the seat surface 32, by means of which asubmarining of the user of the vehicle seat 10 in the case of anaccident-induced deceleration can be avoided or reduced. The restraintdevice 20 is provided as an active anti-submarining device and accordingto the invention is especially preferably designed as a so-called add-onelement which can be selectively integrated into the vehicle seat 10 ornot (depending upon equipping wishes of the customer or thespecifications of the manufacturer). Such an active anti-submariningdevice component can offer an essential contribution to the improvementof occupant protection in the case of a head-on crash. The unit canpreferably be installed as an add-on element in almost all front seatsand also rear seats. In this case, the restraint device 20 can beespecially preferably integrated into the vehicle seat 10 in a so-calledJIT workshop (just-in-time workshop), i.e. in comparatively closeproximity to the final assembly of the vehicle or of the complete seatmodule, by only a fastening of the restraint device 20 on the paddingsupport 34 being carried out, for example via a known fasteningtechnique such as clipping, screwing, riveting, adhesive fastening orthe like. In this case, it is especially advantageous that preferably nowelding operations whatsoever arise and also no modifications tostructural components of the seat section 30 at all are necessary.Furthermore, according to the invention it is especially advantageousthat an identical seat pan 34 or an identical padding support 34 can beused both for a vehicle seat 10 with the restraint device 20 and for avehicle seat 10 without the restraint device 20. As a result of this,the production costs for such vehicle seats 10 can be significantlyreduced or the logistical additional expense for a flexible use of therestraint device 20 on any such vehicle seats is greatly reduced.

In the right-hand part of FIG. 1, a perspective view of a seat pan 34 orof a padding support 34 of a seat section 30 of a vehicle seat 10according to the invention is schematically shown, with a partiallysectioned view of a restraint device 20 according to the invention.

FIG. 2 schematically shows a perspective view of a seat pan 34 or of apadding support 34 of a seat section 30 together with the seat sidesections 31 of the seat section 30 of the vehicle seat 10 according tothe invention, with a view of the restraint device 20 according to theinvention. Also, a part of the seat substructure 15, which in this caseis designed as an adjusting linkage for height adjustment and/orinclination adjustment of the vehicle seat 10 and is connected to theseat side sections 31, is apparent from FIG. 2.

FIGS. 3 and 4 show schematically and sectioned in perspective view theseat pan 34 of the vehicle seat 10 according to the invention with anembodiment of the restraint device 20 in its inactive position 21 (FIG.3) or in its active position 22 (FIG. 4). It is apparent that in theembodiment of the restraint device 20 which is shown this has a housingconsisting of an upper shell 46 and a lower shell 45. The housing of therestraint device 20 for example can comprise a steel material, analuminum material, a magnesium material, a plastic material, or acombination of such materials. It is also apparent that in the activeposition 22 (FIG. 4) the upper shell 46, by means of an actuating means23, is extended upwards, i.e. towards the seat surface 32 (which,however, is not shown in FIG. 4). As a result of this, the pelvic bone(or the ischium hump), which is not shown, of a seat user experiences agreater resistance particularly at an earlier point in time in the caseof a head-on collision so that a submarining of the pelvis or of thehips of the user (forward displacement (displacement in the X-direction)of the so-called H-point or hip-point) can be avoided or its likelihoodor extent significantly reduced. As a result of this, knee airbags whichare preferably arranged in the dashboard and/or measures for belttightening can advantageously be dispensed with or reduced. According tothe invention, this can be especially advantageous particularly for3-door vehicles.

For the positioning of the upper shell 46 of the restraint device 20this comprises a positioning element 24, which in FIGS. 3 and 4 is shownonly as a lever, which is driven by the actuating means 23. In thisembodiment of the restraint device 20 the positioning element 24, duringthe movement between the inactive position 21 of the restraint device 20and the active position 22 of the restraint device 20, is rotated orpivoted around an essentially horizontal rotational axis (extendingparallel to the seat surface 32). As a result of this, the positioningelement 24 is adjusted from a retracted position 21′ which correspondsto the inactive position 21 of the restraint device 20 into an extendedposition 22′ which corresponds to the active position 22 of therestraint device 20 so that the upper shell 46 is extended and, as aresult of this, according to the invention a relatively large impactsurface for the pelvic region of a user in an accident situation isprovided. An alternative embodiment of the positioning element 24 is anessentially plate-form configuration of the positioning element 24. Apositioning element 24 which extends in an essentially flat mannercorresponds to an essentially plate-form configuration of thepositioning element 24, wherein such an element for example is at leasttwice as long (as a rule oriented approximately in the Y-direction) asit is wide (as a rule oriented approximately in the X-direction in itsinactive position), and has a depth of at most a third of its width.Alternatively to such an essentially plate-form element as a positioningelement, it can also be provided according to the invention that a tubewith a plate welded on or another structural element of the restraintdevice 20 serves as a positioning element 24.

The positioning element 24, according to the invention in the exemplaryembodiment according to FIGS. 3 and 4, is rotatably or pivotablyconnected to the lower shell 45 or connected directly to the paddingsupport 34. This last-mentioned alternative connection of thepositioning element 24 is especially advantageous when the lower shell45 is not present. The connection of the positioning element 24 to thelower shell 45 and/or to the padding support 34 can especially beprovided by means of one, or by means of two, or by means of threebearing points, or even by means of more than three bearing points. Twobearing points are advantageously provided on the lateral ends of thepositioning element 24 (in the Y-direction).

According to the invention, the positioning element 24 and/or the uppersection 46 can preferably have a plurality of material zones forbringing about a predetermined deformation behavior or an energydissipation behavior. In this connection, different material zones inparticular have a different deformation behavior. Alternatively orcumulatively, the positioning element 24 and/or the upper section 46is/are provided in an at least partially reversibly deformable manner,wherein the positioning element 24 preferably has a shock absorber or agas-pressure damper. By this means, a different deformation behavior canbe realized for accident situations of differing severity or fordifferent forces to be transmitted between the user of the vehicle seatand the vehicle seat. For example, the deformation of the positioningelement 24 can be provided in a predetermined and at least partiallyreversible manner by means of a gas-pressure damper, and the deformationof the upper section 46 can be provided in an at least partiallyreversible manner by means of elastic deformation.

Alternatively to a positioning element 24 which is rotatable around anessentially horizontal rotational axis, it is also possible according tothe invention, and schematically shown in FIG. 8 based on an alternativeembodiment of the positioning element, that the positioning element 24is rotatable around an essentially vertical rotational axis (essentiallyperpendicularly vertical on the seat surface 32), or is rotatable atleast in parts. In this case, the positioning element 24 for example hastwo reciprocating pistons which are especially cup-like in design andhave a spiral pin-and-slot guide and also are rotatable relative to oneanother and during a rotation execute an axial extending movement alongfor example the common center axis. Alternatively to a rotation around acommon center axis an eccentric rotation of the one reciprocating pistonrelative to the reciprocating piston or relative to anotherreciprocating piston can be also be provided. As a result of this, theinstallation space which is required for the restraint device 20 andalso the weight can be reduced. Locking of the positioning element 24 inthe extended position can be realized via a preferably asymmetricaltoothing (as locking means 25) between the two parts which are rotatablyarranged in relation to each other. Furthermore, an energy dissipationbehavior of a positioning element 24 which is provided in this way canbe brought about relatively simply by arranging in the central region ofthe reciprocating pistons which are designed like cups either a shockabsorber element, or a gas-pressure damper, or a deformation materialsuch as a metal foam, a honeycomb structure, or a similar material whichdissipates energy in the case of a deformation. In the case of the thirdembodiment of the positioning element 24, two or more reciprocatingpiston units can also be provided.

Alternative embodiment variants of the restraint device 20 are shown inFIGS. 4 a, 4 b and 4 c, and also in FIGS. 9 a, 9 b, 9 c, 9 d, 9 e, 9 f,9 g, 9 h, 9 i, 9 j, 9 k and 9 l, in side view or in perspective view asthe case may be.

In FIG. 4 a, a variant of the restraint device 20 with a variableconnection of the upper section 46 is shown in side view. The variableconnection of the upper section 46 of the restraint device 20 isrealized in the region facing away from the positioning element 24 bymeans of a lever 101 which in the initial position (inactive position ofthe restraint device 20) is adjusted or pivoted towards the positioningelement 24. During an activation of the restraint device 20, both thelever 101 and the positioning element 24 are rotated in the oppositerotational direction, wherein the upper section 46 is raised orpositioned both in the region of the positioning element 24 (front) andin the region of the padding support 34 which faces away from thepositioning element 24, as a result of which a particularly goodrestraining action is achieved. When activating the restraint device 20,a pin 102 of the positioning element is also moved in the X-directioninside an elongated hole 103. Such an elongated hole 103 can be designedwith latching recesses which together with the pin 102 form an examplefor a locking means 25. In one variant of the restraint device 20, whichis not shown, the upper section 46, as in FIG. 4 a, is variablyconnected by means of the lever 101, but the lever in the inactiveposition is adjusted in a manner in which it is rotated in the directionaway from the positioning element 24, and in the region of thepositioning element 24 there is no elongated hole 103 but a simplypivotable bearing of the upper section 46 so that the lever 101, theupper section 46 and the positioning element 24 form a four-bar linkage.As a result of this, an optimization of the installation space can beeffected. The four-bar linkage kinematics (or corresponding kinematicswith variable connection of the upper section 46 corresponding to FIG. 4a), compared with the embodiment which is shown in FIGS. 3 and 4, hasthe advantage that the upper shell 46 of the housing of the restraintdevice 20 is also raised in the rear region. This can contribute to animproved restraining functionality. Such four-bar linkage kinematics (orcorresponding kinematics with variable connection of the upper section46 corresponding to FIG. 4 a) according to the invention can be arrangedboth parallel to the direction of travel and transversely to it, or evendiagonally to it.

In FIGS. 4 b (inactive position) and 4 c (active position), a furthervariant of the restraint device 20, with the upper section 46, which inthe case of this variant is linearly movable essentially in onlyoutlined linear guides and which during its linear or at leastessentially linear movement positions the positioning element 24, isshown in perspective view. In this case, the upper section 46 is drivenby the actuating means 23, which for example is provided as a helicalspring, or another form of actuating means 23 is provided, for example apyrotechnically operating linear actuator.

The actuating means 23 can preferably be designed according to theinvention as a pyrotechnic unit, or as a pyrotechnic actuator,preferably a linear actuator. According to the invention, however, it isalternatively or cumulatively also possible that the actuating means 23is designed as a spring-preloaded element (with mechanically storedactuating energy), or is designed as an electromagnetic unit. In thiscase, it is especially advantageously provided according to theinvention that the effective direction of the actuating means 23,despite the relatively close arrangement of the actuating means 23 inrelation to the user of the vehicle seat 10, at no time is directedtowards the user, or to sensitive body parts of the user (such as thetorso or the pelvic region). As a result of this, the risk of injury,for example in the case of a material defect, can be significantlyreduced. The effective direction of the actuating means 23 can beprovided according to the invention either essentially parallel to thedirection of the vehicle or else be established transversely to it, oreven be established diagonally to it.

According to the invention, a locking means (not illustrated) can befastened to the positioning element 24, in particular to the upper endthereof. Such a locking element is preferably provided, according to theinvention, to ensure a good protection function of the restraint device20 such that during an actuation of the actuating means 23 the system isimmediately locked against a movement back into the inactive position 21by means of the locking means. As a result of this, a maximum possibleprotection action in all conceivable situations is achieved even whenthe actual fully extended end position of the restraint device 20 is notreached.

According to the present invention, the restraint device 20 has, in theregion of the positioning element 24 and/or in the region of the uppersection 46 (or of the covering 46 or of the housing cover 46), adeformation element as the energy dissipation means. For this purpose,for example, the upper shell 46 which is set in the active position 22of the restraint device 20 (i.e. extended) can be configured in such away that the forces on the pelvis of the occupant, which occur duringthe head-on crash and arise as a result of the impacting of the occupantupon the seat pan 34, or seat shell 34, or padding support 34, or as aresult of the impacting of the occupant upon the upper shell 46 arenoticeably reduced by directed energy absorption of, for example, theupper shell 46 itself. Furthermore, the positioning element 24 in itsstructure can also be provided in such a way (for example by plates,foams of any type, honeycomb constructions or the like) that the forceswhich occur (at maximum), especially the pelvic forces, are reduced.Furthermore, it is also possible according to the invention for afurther deformation element to be provided in a region of the restraintdevice 20, which region does not belong to the positioning element 24 orto the upper section 46.

In FIGS. 9 a, 9 b, 9 c, 9 d, 9 e and 9 f, two further variants of therestraint device 20 in the active position (FIGS. 9 b, 9 c, 9 e and 9f), or in the inactive position (FIGS. 9 a and 9 d), are shown inperspective view. In this case, a slot 80 is arranged in a locking lever84 which is arranged at the side. The slot 80 has a starting section 81and an end section 82. A bolt 85, which is movable with the positioningelement 24, engages in the slot 80 and during a movement into the activeposition of the restraint device 20 is moved along the slot 80 from thestarting section 81 in the direction towards to the end section 82. Theshape of the slot 80 is now configured in such a way that a reversemovement of the positioning element 24 or of the bolt 85 at least in the(fully) activated position or active position 22 of the restraint device20 is prevented. The difference between the embodiment variant which isshown in FIGS. 9 a, 9 b and 9 c and the embodiment variant which isshown in FIGS. 9 d, 9 e and 9 f is based essentially in the shape of theslot 80, wherein the embodiment variant according to FIGS. 9 a, 9 b and9 c has a more bent shape of the slot 80 while the embodiment variantaccording to FIGS. 9 d, 9 e and 9 f has a more curved shape of the slot80. The locking lever 84 in this case can be pretensioned orspring-preloaded in the direction of its position which corresponds tothe inactive position.

According to a further embodiment variant of the locking means 25, whichis shown in FIGS. 9 g (inactive position) and 9 h (active position),instead of the slot 80 (according to the previously described embodimentvariant) an operating cam 80′, also with a starting section and an endsection 82′ for the bolt 85, is provided, wherein the operating cam hasa recess in the end section in such a way that the bolt 85, which ismoved with the positioning element 24, can also no longer be moved backinto the starting section, or such a reverse movement is highlyimprobable, on account of the force ratios which exist in an accidentsituation. The locking lever 84 in this case can also be pretensioned orspring-preloaded in the direction of its position which corresponds tothe inactive position.

According to a further embodiment variant of the locking means 25, whichis shown in FIGS. 9 i (inactive position) and 9 j (active position), theslot 80 is formed with a starting section 81 which has a reduced clearopening, and an end section 82 which has an enlarged clear opening, insuch a way that the bolt 85 has a smaller diameter in a first axialsection 85′ and interacts with the starting section 81, and that thebolt 85, upon reaching the end section 82 of the slot 80 (which is to becarried out during a movement of the positioning element 24 in thedirection of the active position 22), is pressed with a second axialsection 85″ of the bolt, which has a larger diameter, into the endsection 82 on account of an axial spring-pretensioning of the bolt dueto a spring element 86.

According to a further embodiment variant of the locking means 25, whichis shown in FIGS. 9 k (active position) and 9 l (inactive position), itis provided that the positioning element 24 interacts with the uppersection 46, especially with holes or recesses 46′ in the upper section46, in such a way that upon reaching the active position 22 a reversemovement of the positioning element 24 is prevented. In this case, it isespecially provided that the positioning element 24 has locking lugs24′″ for engaging in the recesses 46′ of the upper section. Furthermore,it can be additionally provided that the upper section 46 has a stop forlimiting the positioning movement of the positioning element 24, forexample an adapted flange.

FIGS. 5, 6, 7 and 7 a each schematically show in side view a detail ofthe restraint device 20 according to the invention with an embodiment ofan energy dissipation means of this type, wherein the lower section 45,the upper section 46, the positioning element 24 and the actuating means(merely indicated by a dashed line) are shown schematically.

In the embodiment of the energy dissipation means or of the deformationelement according to FIG. 5, an energy dissipation means of this type isprovided in the form of a deformation element which is designed as afirst material region 24′ within the positioning element 24. In thiscase, the first material region 24′ is, for example, a material regionwhich is designed such that it can be compressed to a lesser or greaterextent than a second material region 24″ of the positioning element 24.According to the invention, this can take place, for example, by thefirst material region 24′ being provided with a different material thanthe second material region, namely a material which is softer inrelation to plastic deformation. A similar effect is brought about,according to the invention, by a different material structure within thefirst material region 24′ than the second material region 24″. By thismeans, it is possible, for example, for the positioning element 24 to becompressed in the first material region 24′ upon application of forcedue to an acceleration force of a seat user in an accident situation(indicated by an arrow F in FIG. 5) such that, during the accident,kinetic energy is converted by plastic deformation of the first materialregion 24′, and therefore smaller forces or smaller peak values of theforce act on the user and on the rest of the seat structure, as a resultof which the user's health is protected and the loading of the seatstructure is reduced, and therefore the latter can be designed morecost-effectively. As an alternative, it is also possible according tothe invention for a plurality of material regions 24′, 24″ to beprovided within the positioning element 24 such that, in a firstaccident phase, the first material region 24′ is deformed, with thesecond material region 24″ being deformed in a second accident phase(for example due to the action of a greater force). By this means, it ispossible for a graduated deformation behavior of the deformation element24′, 24″ to be realized, said deformation behavior reacting particularlyeasily and flexibly to different accident situations and force ratios(for example caused by users of differing height and weight and bydifferent sitting positions of the same prior to the accident). Such aplurality of material regions 24′, 24″ can be provided, for example, inthe form of a combination of steel and aluminum or in the form of acombination of magnesium and aluminum.

FIG. 6 schematically shows in side view an embodiment variant of thedeformation element in the form of a shock absorber 51 or gas-pressuredamper 51. This permits a partially reversible movement, i.e.springing-back movement, of the positioning element 24 on account of anaccident-induced loading situation.

FIG. 7 shows an embodiment variant of the deformation element as adeformation element which is connected to the upper section 46 (or isprovided as part of the upper section 46) and is denoted by thereference number 52. In the event of a force acting on the upper section46 on the part of the user, the upper section 46 can firstly be deformeditself (not illustrated) and can secondly be pressed downward bycompression of the positioning element 24 (for example as per theembodiment according to FIG. 5 or 6), as a result of which thedeformation element denoted by the reference number 52 is plasticallydeformed. As an alternative thereto, as another embodiment of adeformation element, an elongated hole 53 with a shearing web (notillustrated in detail) which normally inhibits the movement of a bearingelement (here, for example, a bolt) can be formed. In the event of anaccident, a web of this type is deformed by impact.

FIG. 7 a merely shows the positioning element 24 in a sectionalillustration, the positioning element 24 being shown as beingconstructed (in the example shown) from two parts which are connected toeach other by a spring element as the energy dissipation means or energystorage means.

It is likewise provided according to the invention that the embodimentvariants according to FIG. 5 and/or according to FIG. 6 and/or accordingto FIG. 7 and/or according to FIG. 7 a are combined with one another. Itis thereby possible to react particularly flexibly to different loadingsituations.

FIG. 8 schematically shows in side view a detail of the restraint device20 according to the invention with a positioning element 24 which is atleast partially rotatable about a rotational axis essentiallyperpendicularly vertical with respect to the seat surface. In the caseof the cup-like cylinder elements which are rotatable spirally relativeto each other, a deformation element in the form of a material region24′, 24″ or else in the form of a shock absorber 51 or in the form of aspiral spring or in general in the form of a spring element can beprovided in the central region. In the embodiment of the locking means25, which is schematically shown in FIG. 8, an asymmetrical toothing 41is provided between the two telescopically inter-engaging cylinderelements which together form the positioning element 24. In this case,the asymmetrical toothing 41 is designed in such a way that an extendingmovement of the cylinder elements is possible, but no reverse movement.According to a variant of this embodiment of the locking means 25, whichis not shown, it is provided that a pin slot guide, or pin guide track,which is spirally arranged in the region of the circumference of thecylinder elements, in its end section which corresponds to the activeposition (extended cylinder elements) has a reduced pitch which in theevent of a release of the restraint device 20 leads to the prevention ofthe movement into the inactive position of the restraint device.

LIST OF DESIGNATIONS

-   10 Vehicle seat-   15 Seat substructure-   16 Floor sub-assembly-   20 Restraint device-   21 Inactive position-   21′ Retracted position-   22 Active position-   22′ Extended position-   23 Actuating means-   24 Positioning element-   24′, 24″ Material regions of the positioning element as the    deformation elements-   30 Seat section-   31 Seat side sections-   32 Seat surface-   33 Padding/seat cushion-   34 Seat pan/padding support/seat bucket-   45 Lower shell-   46 Upper shell-   51 Shock absorber/gas-pressure damper as the deformation elements-   52 Material region as the deformation element-   53 Elongated hole as the deformation element-   80 Slot-   80′ Operating cam-   81 Starting section-   82 End section of the slot-   82′ End section of the operating cam-   84 Locking lever-   85 Bolt-   85′ First axial section of the bolt (reduced diameter)-   85″ Second axial section of the bolt (enlarged diameter)

1. A vehicle seat having a seat section and a restraint device forpreventing submarining of a passenger on the vehicle seat in the case ofan accident-induced deceleration comprising: a seat section having apadding defining a seat surface, and a padding support located beneaththe padding, and the seat section has seat side sections extending inthe longitudinal direction of the vehicle; a restraint device having aretracted inactive position and, an extended active position, whereinthe restraint device includes a positioning element disposed between thepadding support and the padding and located a distance from the seatside sections, and an upper section located between the positioningelement and the padding, and one of the positioning element and theupper section has at least one energy dissipation element, such that arotation of at least one part of the positioning element around anessentially vertically extending axis is provided between the retractedposition and the extended position of the positioning element and thepositioning element is telescopically extendable.
 2. The vehicle sea asclaimed in claim 1, wherein the restraint device has a reversiblyoperating actuator arranged between the padding support and the paddingand the actuator operates before an accident-induced deceleration. 3.The vehicle seat as claimed in claim 2 wherein the positioning elementis provided in a manner movable by the actuator, wherein the positioningelement is adjusted by the actuator from a retracted position whichcorresponds to the inactive position of the restraint device into anextended position which corresponds to the active position of therestraint device.
 4. The vehicle seat as claimed in claim 3 wherein arotation around an essentially horizontally extending axis is providedbetween the retracted position and the extended position of thepositioning element, wherein the positioning element is a generallyplanar element.
 5. The vehicle seat as claimed in claim 4, wherein therotation around the essentially horizontally extending axis is in thedirection of travel of the vehicle seat.
 6. The vehicle seat as claimedin claim 1 wherein the positioning element includes at least one of ashock absorber and a gas-pressure damper.
 7. The vehicle seat as claimedin claim 1 wherein the restraint device has a deformation element.
 8. Avehicle seat having a seat section and a restraint device for preventingsubmarining of a passenger on the vehicle seat in the case of anaccident-induced deceleration comprising: a seat section having apadding defining a seat surface, and a padding support located beneaththe padding, and the seat section has seat side sections extending inthe longitudinal direction of the vehicle; a restraint device having aretracted inactive position and an extended active position, wherein therestraint device includes a positioning element disposed between thepadding support and the padding and located a distance from the seatside sections, and an upper section located between the positioningelement and the padding, and one of the positioning element and theupper section has at least one energy dissipation element, and thepositioning element has a plurality of material zones of a differentmaterial, and the different material zones each have a differentdeformation behavior.
 9. A vehicle seat having a seat section and arestraint device for preventing submarining of a passenger on thevehicle seat in the case of an accident-induced deceleration comprising:a seat section having a padding defining a seat surface, and a paddingsupport located beneath the padding, and the seat section has seat sidesections extending in the longitudinal direction of the vehicle; arestraint device having a retracted inactive position and an extendedactive position, wherein the restraint device includes a positioningelement disposed between the padding support and the padding and locateda distance from the seat side sections, and an upper section locatedbetween the positioning element and the padding, and one of thepositioning element and the upper section has at least one energydissipation element; and a locking device movable by the movement of thepositioning element, and the locking device has a slot and a bolt andthe bolt has an axial first section with reduced diameter, and an axialsecond section with enlarged diameter, and an axial movement of the boltbrings about the locking.